The Tyranids are unlike other armies in 40k in that they're a race of creatures that share a single hive mind. That lets them manifest abilities across different parts of the battlefield thanks to their synaptic links. In this preview, we get a look at a pair of new abilities that they're getting soon.
From the article:
While covert kill teams take on desperate missions in the darkness to influence the Octarius War, the escalating carnage on the battlefields see billions of lives fed into the meat grinder as the Orks and Tyranids vie for dominance.
In a bid for greater tactical efficiency, the Hive Mind has developed synaptic abilities for its most critical bioforms. With War Zone Octarius – Book 1: Rising Tide on the way, we’ve got vital intel on some of the Tyranids’ new capabilities.